A television show, movie, internet video, or other similar content may be stored on a disc or in other memory using a container or wrapper file format. The container format may be used to specify how multiple different data files are to be used. The container format for a video may identify different data types and describe how they are to be interleaved when the video is played. A container may contain video files, audio files, subtitle files, chapter-information files, metadata, and other files. A container also typically includes a file that specifies synchronization information needed for simultaneous playback of the various files.
One format for digital video files is the DVD-Video format. Another format for digital video files is Audio Video Interleaved (“AVI”). Audio may be stored in various formats, such as the PCM, DTS, MPEG-1 Audio Layer II (MP2), or Dolby Digital (AC-3) formats.
A multimedia video generally includes a large amount of perceptual information, i.e., information such as images and sounds that are perceived by viewers. The frames of a video file may show humans, who may or may not be actors, and a wide variety of nonhuman objects. A nonhuman object may be a background, such as a natural indoor or outdoor location, or a professional stage or set. A nonhuman object may also be a prop or other visual element in front of the background object. Yet another type of nonhuman object that may be shown in a video frame is text. For instance, words spoken by humans may be displayed as text in a particular area of the frames. Segments of an audio file may be synchronously played with the display of video frames. These segments may include spoken words, music, and a wide variety of sound effects.
While an audio-video file may be as short as a few minutes, the typical video, such as a television show or a full length movie, ranges in length from 20 minutes to over two hours. The typical video may include many scenes, each corresponding with a particular segment of the video. For example, a movie may have between 50 and 200 scenes. A minor scene may be one minute or less. A major scene may be three or more minutes. Each scene may include many frames and may include one or more camera shots. A scene may be accompanied by spoken dialog, a particular musical score or set of sound effects, or a combination of sound types. Particular human and nonhuman objects may appear in a scene. A scene may be intended by the creator to invoke particular emotions or moods, or to convey a theme of the story.